I have a problem where a site, which is normally serving about 300
connections, occasionally has an error where static files do not
download (or at least it seems like it's only static files). For
example let's say there is 40 different objects (images, css, js, etc)
that need to download. They will all download except for one image or
css file, or sometimes even a file with extension "axd" (which I have
come to understand is a.net placeholder for javascript). The site uses
.net 2.0 with VBScript. I do not think it is a bandwidth issue as the
load on my firewall is less than 2%. I have searched for a week and
not found anything on this issue, and am just about ready to call
Microsoft. Additional info: I'm running windows network load balancing
between two servers. Both run Windows 2003 SP1 w/ IIS 6. There is no
ISAPI filters on any of the sites besides the normal ASP .Net 2.0 one
that runs in low priority. I'm not using HTTP compression.

If ANYONE has anything that can contribute or a place to start looking,
I would be more than grateful (especially if you are from Microsoft
*crosses fingers*). If you need any additional information I can let
you know whatever you need (within secure reason).

Thanks!

Re: Static files occasionally do not download by David

David
Tue Jan 16 02:30:39 CST 2007

When you notice a file that fails to download, you know the exact
filename that failed to download and you should check on the
appropriate IIS6 server in the NLB "cluster" to see what the server
thinks of the file download. You know the client thinks the file is
"not found", but what exactly happened?
- A successful download should show up in the
%SYSTEMROOT%\System32\LogFiles\W3SVC#\*.log files, regardless if it
came from the HTTP.SYS Kernel Response cache or from the FileSystem.
- An error processing the request in IIS should also show up in that
log file (though you say it's static file, so it should not be
"occassionally" failing).
- An error transmitting the response over the network should show up in
%SYSTEMROOT%\System32\LogFiles\HTTPERR\*.log

And for more granularity, you can take a Network Trace of the entire
sequence of request/response during the exact failure. Then, you will
have the TCP traffic as well, and you can spot if the client or server
inappropriately dropped the file.

FYI: This is a free public support forum. We try our best to help, but
there are no guarantees nor obligations. If you have expectations for
solutions within a known time-period, then you should contact and pay
for a Microsoft PSS Support Case.

FYI: In general, I think it is easier to directly troubleshoot and
narrow down what exactly "occassionally do not download" actually
means, than to blindly pattern-match for a solution to an ill-defined
problem. There are tons of reasons why a given resource may not
download from a web server - gathering support data from log files is
crucial in narrowing down the problem scope and better define the
problem - which then helps identify the solution.

http://blogs.msdn.com/david.wang/archive/2005/12/31/HOWTO_Basics_of_IIS6_Troubleshooting.aspx




//David
http://w3-4u.blogspot.com
http://blogs.msdn.com/David.Wang
//



videogamemaster@hotmail.com wrote:
> I have a problem where a site, which is normally serving about 300
> connections, occasionally has an error where static files do not
> download (or at least it seems like it's only static files). For
> example let's say there is 40 different objects (images, css, js, etc)
> that need to download. They will all download except for one image or
> css file, or sometimes even a file with extension "axd" (which I have
> come to understand is a.net placeholder for javascript). The site uses
> .net 2.0 with VBScript. I do not think it is a bandwidth issue as the
> load on my firewall is less than 2%. I have searched for a week and
> not found anything on this issue, and am just about ready to call
> Microsoft. Additional info: I'm running windows network load balancing
> between two servers. Both run Windows 2003 SP1 w/ IIS 6. There is no
> ISAPI filters on any of the sites besides the normal ASP .Net 2.0 one
> that runs in low priority. I'm not using HTTP compression.
>
> If ANYONE has anything that can contribute or a place to start looking,
> I would be more than grateful (especially if you are from Microsoft
> *crosses fingers*). If you need any additional information I can let
> you know whatever you need (within secure reason).
>
> Thanks!


Re: Static files occasionally do not download by videogamemaster

videogamemaster
Tue Jan 16 15:11:15 CST 2007

I completely understand, and as I said I'm preparred to give anything
that will solve the issue on this one.

I have imported our logs into SQL in order to make it easier to find
the object when it fails to download. I found one instance yesterday
where an image failed to download, getting a time out. In the web
logs, I get a status 200 for that image, with time-taken as 62
milliseconds. The browser took 13.7967 seconds and then timed out on
the object. The image is only 430 bytes.

Why would the web logs show that the image was processed in 62
milliseconds but the browser timed out?

An update on this - I pointed the production ip to just a single web
server today instead of to the WLBS clustered ip - so far today I
haven't had the issue, although I'm not counting my chickens yet.
Obviously this is not a permanent fix in any case, I just wanted to see
if the WLBS was the issue.

Thanks for any help you can provide


David Wang wrote:
> When you notice a file that fails to download, you know the exact
> filename that failed to download and you should check on the
> appropriate IIS6 server in the NLB "cluster" to see what the server
> thinks of the file download. You know the client thinks the file is
> "not found", but what exactly happened?
> - A successful download should show up in the
> %SYSTEMROOT%\System32\LogFiles\W3SVC#\*.log files, regardless if it
> came from the HTTP.SYS Kernel Response cache or from the FileSystem.
> - An error processing the request in IIS should also show up in that
> log file (though you say it's static file, so it should not be
> "occassionally" failing).
> - An error transmitting the response over the network should show up in
> %SYSTEMROOT%\System32\LogFiles\HTTPERR\*.log
>
> And for more granularity, you can take a Network Trace of the entire
> sequence of request/response during the exact failure. Then, you will
> have the TCP traffic as well, and you can spot if the client or server
> inappropriately dropped the file.
>
> FYI: This is a free public support forum. We try our best to help, but
> there are no guarantees nor obligations. If you have expectations for
> solutions within a known time-period, then you should contact and pay
> for a Microsoft PSS Support Case.
>
> FYI: In general, I think it is easier to directly troubleshoot and
> narrow down what exactly "occassionally do not download" actually
> means, than to blindly pattern-match for a solution to an ill-defined
> problem. There are tons of reasons why a given resource may not
> download from a web server - gathering support data from log files is
> crucial in narrowing down the problem scope and better define the
> problem - which then helps identify the solution.
>
> http://blogs.msdn.com/david.wang/archive/2005/12/31/HOWTO_Basics_of_IIS6_Troubleshooting.aspx
>
>
>
>
> //David
> http://w3-4u.blogspot.com
> http://blogs.msdn.com/David.Wang
> //
>
>
>
> videogamemaster@hotmail.com wrote:
> > I have a problem where a site, which is normally serving about 300
> > connections, occasionally has an error where static files do not
> > download (or at least it seems like it's only static files). For
> > example let's say there is 40 different objects (images, css, js, etc)
> > that need to download. They will all download except for one image or
> > css file, or sometimes even a file with extension "axd" (which I have
> > come to understand is a.net placeholder for javascript). The site uses
> > .net 2.0 with VBScript. I do not think it is a bandwidth issue as the
> > load on my firewall is less than 2%. I have searched for a week and
> > not found anything on this issue, and am just about ready to call
> > Microsoft. Additional info: I'm running windows network load balancing
> > between two servers. Both run Windows 2003 SP1 w/ IIS 6. There is no
> > ISAPI filters on any of the sites besides the normal ASP .Net 2.0 one
> > that runs in low priority. I'm not using HTTP compression.
> >
> > If ANYONE has anything that can contribute or a place to start looking,
> > I would be more than grateful (especially if you are from Microsoft
> > *crosses fingers*). If you need any additional information I can let
> > you know whatever you need (within secure reason).
> >
> > Thanks!


Re: Static files occasionally do not download by David

David
Wed Jan 17 22:05:03 CST 2007

Assuming that the log file entry in the web logs correlates to your
missing download -- it means that IIS itself successfully sent those
430 bytes to the network layer within 62ms of the request coming in,
and the network layer acknowledged its receipt without error. Whether
those bytes actually made it to the client -- totally unknown and
uncontrollable by IIS.


//David
http://w3-4u.blogspot.com
http://blogs.msdn.com/David.Wang
//


videogamemaster@hotmail.com wrote:
> I completely understand, and as I said I'm preparred to give anything
> that will solve the issue on this one.
>
> I have imported our logs into SQL in order to make it easier to find
> the object when it fails to download. I found one instance yesterday
> where an image failed to download, getting a time out. In the web
> logs, I get a status 200 for that image, with time-taken as 62
> milliseconds. The browser took 13.7967 seconds and then timed out on
> the object. The image is only 430 bytes.
>
> Why would the web logs show that the image was processed in 62
> milliseconds but the browser timed out?
>
> An update on this - I pointed the production ip to just a single web
> server today instead of to the WLBS clustered ip - so far today I
> haven't had the issue, although I'm not counting my chickens yet.
> Obviously this is not a permanent fix in any case, I just wanted to see
> if the WLBS was the issue.
>
> Thanks for any help you can provide
>
>
> David Wang wrote:
> > When you notice a file that fails to download, you know the exact
> > filename that failed to download and you should check on the
> > appropriate IIS6 server in the NLB "cluster" to see what the server
> > thinks of the file download. You know the client thinks the file is
> > "not found", but what exactly happened?
> > - A successful download should show up in the
> > %SYSTEMROOT%\System32\LogFiles\W3SVC#\*.log files, regardless if it
> > came from the HTTP.SYS Kernel Response cache or from the FileSystem.
> > - An error processing the request in IIS should also show up in that
> > log file (though you say it's static file, so it should not be
> > "occassionally" failing).
> > - An error transmitting the response over the network should show up in
> > %SYSTEMROOT%\System32\LogFiles\HTTPERR\*.log
> >
> > And for more granularity, you can take a Network Trace of the entire
> > sequence of request/response during the exact failure. Then, you will
> > have the TCP traffic as well, and you can spot if the client or server
> > inappropriately dropped the file.
> >
> > FYI: This is a free public support forum. We try our best to help, but
> > there are no guarantees nor obligations. If you have expectations for
> > solutions within a known time-period, then you should contact and pay
> > for a Microsoft PSS Support Case.
> >
> > FYI: In general, I think it is easier to directly troubleshoot and
> > narrow down what exactly "occassionally do not download" actually
> > means, than to blindly pattern-match for a solution to an ill-defined
> > problem. There are tons of reasons why a given resource may not
> > download from a web server - gathering support data from log files is
> > crucial in narrowing down the problem scope and better define the
> > problem - which then helps identify the solution.
> >
> > http://blogs.msdn.com/david.wang/archive/2005/12/31/HOWTO_Basics_of_IIS6_Troubleshooting.aspx
> >
> >
> >
> >
> > //David
> > http://w3-4u.blogspot.com
> > http://blogs.msdn.com/David.Wang
> > //
> >
> >
> >
> > videogamemaster@hotmail.com wrote:
> > > I have a problem where a site, which is normally serving about 300
> > > connections, occasionally has an error where static files do not
> > > download (or at least it seems like it's only static files). For
> > > example let's say there is 40 different objects (images, css, js, etc)
> > > that need to download. They will all download except for one image or
> > > css file, or sometimes even a file with extension "axd" (which I have
> > > come to understand is a.net placeholder for javascript). The site uses
> > > .net 2.0 with VBScript. I do not think it is a bandwidth issue as the
> > > load on my firewall is less than 2%. I have searched for a week and
> > > not found anything on this issue, and am just about ready to call
> > > Microsoft. Additional info: I'm running windows network load balancing
> > > between two servers. Both run Windows 2003 SP1 w/ IIS 6. There is no
> > > ISAPI filters on any of the sites besides the normal ASP .Net 2.0 one
> > > that runs in low priority. I'm not using HTTP compression.
> > >
> > > If ANYONE has anything that can contribute or a place to start looking,
> > > I would be more than grateful (especially if you are from Microsoft
> > > *crosses fingers*). If you need any additional information I can let
> > > you know whatever you need (within secure reason).
> > >
> > > Thanks!